Scene length confusion

Post a screenshot of what you're seeing and what you expect to see there. If you select a clip the info inspector is display information about the clip that is separate from any project.

The video isn't actually video, but a still image, which is assigned by FCP a frame rate of 60fps, though stills of course don't actually have a frame rate. The title shows a duration of 1:20, one second and 20 frames, which is based on the project duration. Titles have no frame rate. The still image is 1:50, one second and 50 frames, which on a 60fps item is the same duration as 1:20 at 24fps. What really matters is the duration in the project, which appears at the bottom of the project. The title duration will match the project duration. If you turn on the clip skimmer in the timeline and skim the two items you'll see the difference in frame counts.

TYou can make the dashboard display as a frame count starting at zero. The clips themselves can't be.

TThe dashboard normally displays the timecode of the project. That can be set to display as a frame count, 60 frames for your two and a half seconds at 24fps. If you select a clip or group of clips in the timeline, the duration of the selection is displayed at the bottom of the timeline window. The display will show you a frame count, number of frames for the selection, total number of frames for the project. The inspector will also show the duration based on the frame count, but this can be very misleading because that the frame count based not on the project's 24fps, but the actual number of frames in the clip. So a clip that's two seconds at 24fps will be 48 frames in duration while a clips that's two seconds at 60fps will have a duration of 120 frames. In the timeline the selection duration for each clip will be 48 because it's based on the frame count of the project.